I know you're going to say that we all come from cavemen, and it's true, we do. But some members of my family are still cavemen... today. Not the kind of massive blunt warriors, like our ancestors must have been to survive Natural Selection, but the sort of weekenders living in Paris travelling for cool weekends down to the banks of the Loire River, some 200 miles southwest of the capital city.
They are called troglodytes.
The limestone cliffs by the river banks harbor several rock caves formations that have been restored into basic habitat, no windows and not much comfort, as walls and floors are mostly limestone and other carved stones. I have never visited any other than my uncle's house, but I heard that some people have covered their digs with comfy carpets and plush cushions, but I think that would defeat the purpose.
My family's house has only one large room, sort-of kind-of a rounded shape, very few angles, much less partitions, and is at the same time bedroom, living space, and kitchen. They don't have running water inside but a spring-fed well in the front patio of the cave, and the city has long ago installed mandatory outhouses linked to the town sewage, please. The temperature inside is always cool, that's why my family only comes in the summer months, it's impossible to heat the place in other seasons with space heaters.
The irregular ceiling is 16 feet high, and in some area it shoots up to 30 feet high, does not help with the room temperature. Since there are no windows, except for the front glass double door, you would think that it would be very dark inside, when it's in fact very bright and white, due to the light reflecting on the blinding hue of the cream-colored stone walls.
As kids we thought the cave house was really aloof, just one giant room of about 700 square feet, with a few corners, where you could always see everywhere at all times. No bathroom, no shower, you had to go outside and wash at the, very cold, water well, where my uncle had built a little privacy fence and a basin to brush teeth, and not much else.
They always leave Paris on Saturday morning, after a shower, to return Sunday night, and take a shower. The times when they did spend an entire week vacation there, they showered at the local public pool, or at the gymnasium at the high school that was equipped with cave people in mind, knowing they would need washrooms and other facilities in the summer when school was out.
Besides, there was a hose right by the well. I would not want you to think that French people don't wash.
You could not stick a nail in the walls, so nothing was attached, no picture frames, no bookshelves, no kitchen rack; everything had to be self standing. Most of the furniture had to be adapted to the rugged floors and uneven surfaces, and everything always looked a bit crooked, this was fun. We used to eat outside under a large canopy of dry palms with cute little paper lanterns dangling in the wind, it was lovely. They had electricity from the grid, and even a fridge, but this was fairly recent and was only installed in the '70s; before that it was all candles and gas lanterns.
No mosquitoes there, as the Loire River nearby does not attract them a bit. There is a large tree near the cave entrance that shelters tiny black bats that only come out at night to circle around, not minding the humans. From the cave, you could see boats up and down stream, quietly traveling for pleasure, some flat barges (péniches), a few canoes, not very many sailboats, not enough wind I suppose.
The Loire River valley is a much protected rural setting, quiet and peaceful like an impressionist painting. Many castles have been built along its banks, over one hundred of them. Most are majestic masterpieces, many are former royal residences, some are still owned by royals, way down the line ones. Several are museums and some are hotels. It is believed that the first inhabitants of the caves in modern times were the workers building the many chateaux around.
The definite must-see ones include the largest one of all, the Château de Chambord (16th century), the Château de Chenonceau (15th century, straddling the Cher River), Villandry (magnificent gardens: http://www.chateauvillandry.fr/jardins/visite-virtuelle/), Azay-le-Rideau (set in the middle of an island), and Château d'Amboise (where a few French kings lived and died.)
You could easily spend several months in the region and visit a different chateau each day. Some of the caves in the troglodyte villages are also open to the public for visits; museums or wineries, all have interesting stories hidden in their walls.
I will always fondly remember visiting my aunt and uncle at their cave, feeling like a wild child, almost a Flintstone.